<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Http\Requests\Admin\StoreProgramRequest;
use App\Http\Requests\Admin\UpdateProgramRequest;
use App\Models\Program;
use App\Services\AuditLogService;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\View\View;

class ProgramController extends Controller
{
    public function index(Request $request): View
    {
        $query = Program::with('creator')
            ->withCount(['attendances', 'programParticipants'])
            ->latest();

        // Admin program hanya nampak program sendiri
        if (auth()->user()->isAdminProgram()) {
            $query->where('created_by', auth()->id());
        }

        if ($request->filled('search')) {
            $query->where(function ($q) use ($request) {
                $q->where('title', 'like', '%' . $request->search . '%')
                  ->orWhere('organizer', 'like', '%' . $request->search . '%')
                  ->orWhere('location', 'like', '%' . $request->search . '%');
            });
        }

        if ($request->filled('status')) {
            $query->where('status', $request->status);
        }

        $programs = $query->paginate(15)->withQueryString();

        return view('admin.programs.index', compact('programs'));
    }

    public function create(): View
    {
        return view('admin.programs.create');
    }

    public function store(StoreProgramRequest $request): RedirectResponse
    {
        $program = Program::create([
            ...$request->validated(),
            'created_by' => auth()->id(),
        ]);

        AuditLogService::log('program.created', $program);

        return redirect()
            ->route('admin.programs.show', $program)
            ->with('success', 'Program "' . $program->title . '" berjaya ditambah.');
    }

    public function show(Program $program): View
    {
        $this->authorize('view', $program);

        $program->load([
            'qrCode',
            'certificateTemplate',
            'questionnaire.questionnaireSet.questions',
        ]);

        // Consolidate into 2 queries instead of 6 separate COUNTs
        $ppStats = \DB::table('program_participants')
            ->where('program_id', $program->id)
            ->selectRaw("COUNT(*) as total, SUM(is_pre_registered) as pre_registered, SUM(registration_source = 'walk_in') as walk_in")
            ->first();

        $certStats = \DB::table('certificates')
            ->where('program_id', $program->id)
            ->selectRaw("COUNT(*) as total, SUM(status IN ('generated','emailed','downloaded')) as cert_generated")
            ->first();

        $stats = [
            'total_participants'     => (int) ($ppStats->total          ?? 0),
            'pre_registered'         => (int) ($ppStats->pre_registered ?? 0),
            'walk_in'                => (int) ($ppStats->walk_in        ?? 0),
            'total_attendances'      => $program->attendances()->count(),
            'total_certificates'     => (int) ($certStats->total        ?? 0),
            'generated_certificates' => (int) ($certStats->cert_generated ?? 0),
        ];

        return view('admin.programs.show', compact('program', 'stats'));
    }

    public function edit(Program $program): View
    {
        $this->authorize('update', $program);

        return view('admin.programs.edit', compact('program'));
    }

    public function update(UpdateProgramRequest $request, Program $program): RedirectResponse
    {
        $this->authorize('update', $program);

        $old = $program->only([
            'title', 'status', 'checkin_start_at', 'checkin_end_at',
            'ecert_download_start_at', 'ecert_download_end_at',
        ]);

        $program->update($request->validated());

        AuditLogService::log('program.updated', $program, $old);

        return redirect()
            ->route('admin.programs.show', $program)
            ->with('success', 'Maklumat program berjaya dikemas kini.');
    }

    public function destroy(Program $program): RedirectResponse
    {
        $this->authorize('delete', $program);

        if ($program->attendances()->exists()) {
            return back()->with('error', 'Program tidak boleh dipadam kerana sudah ada rekod kehadiran.');
        }

        $title = $program->title;
        AuditLogService::log('program.deleted', $program);
        $program->delete();

        return redirect()
            ->route('admin.programs.index')
            ->with('success', 'Program "' . $title . '" berjaya dipadam.');
    }

    public function publish(Program $program): RedirectResponse
    {
        $this->authorize('update', $program);

        if ($program->status !== 'draft') {
            return back()->with('error', 'Hanya program berstatus Draf boleh diterbitkan.');
        }

        $program->update(['status' => 'published']);
        AuditLogService::log('program.published', $program);

        return back()->with('success', 'Program berjaya diterbitkan.');
    }

    public function close(Program $program): RedirectResponse
    {
        $this->authorize('update', $program);

        if ($program->status !== 'published') {
            return back()->with('error', 'Hanya program berstatus Diterbitkan boleh ditutup.');
        }

        $program->update(['status' => 'closed']);
        AuditLogService::log('program.closed', $program);

        return back()->with('success', 'Program berjaya ditutup.');
    }
}